Internal-combustion heater with expansible fuel reservoir



April 27, 1948. H. J. DE N. M coLLuM 40, v

INTERNAL-COBBUSTION HEATER WITH EXPANSIBLE FUEL RESERVOIR Filed May 7, 1943 'Q am;

a fa write automobile heating Patented Apr. 27, 1948 UNITED STATES f PATENT OFFICE INTERNAL- COMBUSTION EXPANSIBLE FUEL McCollum,

McCollum, deceased,

ner Corporation, Virginia HEATER WITH RESERVOIR Chicago, 111.; Thelma Application May 7, 1943, Serial No. 486,019 6 Claims. (01. 126-116) My invention relates to heating apparatus and more particularly to an internal combustion type of heating apparatus especially adapted for, but not limited to, use on automobiles.

An object of my invention is to provide a new and improved heating apparatus for automobiles which will operate independently of the automobile engine cooling system.

Another object of my invention is to provide new and improved heating apparatus which will continue to operate after the automobile engine has been stopped.

Another object of my invention is to provide apparatus of the internal combustion type having a pressure reservoir providing for operation of the heating apparatus in- I dependently of the automobile engine.

Another object of my invention is to provide new and improved heating apparatus of the internal combustion type which is supplied with fuel from the engine fuel pump, but which will operate for a predetermined length of time after this fuel pump is stopped.

Other objects and advantages will become apparent as the description proceeds.

In the drawings:

Fig. 1 is a diagrammatic representation of my invention showing the internal combustion heater in longitudinal section; and

Fig. 2 is a wiring diagram of the heater of the present invention.

In Fig. 1, I have indicated a conventional automobile engine H] as E? to which the.usual carburetor I 4 is attached. An air cleaner I6 is ailixed to the air inlet of the carburetor I4 and fuel is supplied to this carburetor through a pipe l8 which connects the usual float bowl 20 with a fuel pump 22. A second pipe 24 connects the fuel pump 22 with the usual gasoline tank 26. The pump 22 is preferably of the' conventional diaphragm type in which the diaphragm is moved on its intake stroke by an engine driven cam and is returned by a spring which determines the pressure under which the i'uelis forced to the engine carburetor.

A T28 is located intermediate the pipe l8 and serves to connect this pipe with a resilient fuel reservoir indicated generally by the reference numeral I and a solenoid valve 30 in a fuel supply line 32'leading to a fuel jet 34 located in the inlet end of the induction tube 36 of a heater indicated generally by reference numeral 38. A filter 40 is preferably interposed between the solenoid valve 80 and Jet 34 to protect the latter against ll having an intake manifold any dirt or other'impurities contained in the gasoline. v

The heater 38 is 01' the internal combustion type and comprises in general a casing 42 having an inlet end 44 attached to the discharge outlet 46 of a blower 48. This blower delivers air to the lefthand end of the casing 42 under low pressure and may be of any conventional type, such as the centrifugal type shown in the drawing. An electric motor 56 drives the blower 46 andis designed to operate from the usual automobile electrical system. a

A combustion chamber 52 is located in the casing 42 and supplied with a mixture of fuel and air by the induction tube 36. This combustion chamber has a circular wall and the induction tube 36 delivers the combustible mixture in a direction tangential to this wall so that the combustible mixture tends to whirl about the longitudinal axis of the combustion chamber. The

tube 36 has a portion of appreciable length located within the combustion chamber and this portion of the tube serves as a means for preheating the combustible mixture. A housing 54 is attached to the lefthaind end of the combustion chamber and provides a pocket 56 which communicates with the combustion chamber through an opening 58 in the end wall thereof. An igniter block 68 is threaded into a 0 wall of the housing 54 and has an igniting coil 62 for igniting combustible mixture in the pocket 56. It will be apparent from an inspection of Fig. 1 that the outlet end 68 of the induction tube 36 is directed toward the opening 58 whereby 3 mixture leaving this induction tube tends to enter the pocket 66 where it will come in contact with the igniting coil 62.

Hot products of combustion issue from the righthand end of the combustion chamber 52 through the opening 64 in an annulus 66 which serves to prevent the escape of liquid fuel from the combustion chamber. These hot products of combustion enter the lefthand end of a cylindrical sleeve 68 located in a circularly arranged series of ventilating air tubes 16 mounted in partitions 12 and 14. The hot products of combustion entering the sleeve 68 are mixed therein with secondaryair admitted to the large end of this sleeve through openings 18 in the partition 12.

The mixture 01' hot products of combustion and secondary air is discharged from the righthand or smaller end of the sleeve 68 and flows backwardly along this sleeve, as shown by the arrows in Fig. 1. The ventilating air tubes 10 are located between the sleeve 68 and a generally cylindrical casing I8 and these tubes are in spaced relation to the sleeve and casing and to each other so that the hot gases issuing from the righthand end of the sleeve 88 can completely surround the ventilating air tubes I as these gases flow to the left, as viewed in Fig. '1. The casing 18 has an annular enlargement 80 which functions somewhat as an exhaust manifold. The cooled gases fiow into this enlargement 80 and are discharged to atmosphere through an exhaust pipe 82 communicating with this enlargement.

Part of the ventilating air supplied by the blower 48 flows upwardly in a sheet metal sleeve 84 surrounding the igniter plug 80.. When the heater is first turned on, the heat of the igniter plug serves to preheat the air flowing between this plug and the sleeve 84 and since this air is used for combustion purposes, such preheating facilities prompt ignition of the fuel mixture in the combustion chamber. This combustion air flows from the upper end of sleeve 84 through a passage 86 provided by a sheet metal cover 88 and into the upper end of the induction tube 36. This induction tube has an appreciable portion of its length in the combustion chamber and after the heater has been in operation for a short length of time, this portion of the induction tube supplies the requisite preheating to the fuel mixture before it enters the combustion chamber.

It is to be particularly noted that the induction tube 38 has no restriction therein and affords a minimum resistance to air flow therethrough. The passages leading to the upper end of this induction tube are large and offer minimum resistance to flow so that a low pressure blower is capable of supplying adequate air for. combustion purposes as well as for ventilating purposes.

Most of the air supplied by the blower 48 is used for ventilating and heating purposes and passes around the combustion chamber 52 from which it absorbs some heat. This air then enters the venftilating air tubes I0 where it receives further heat from the hot products of combustion discharged from the combustion chamber. The heated air leaving the righthand ends of the ventilating air tubes I0 then enters the tapered outlet end 80 of the heater casing and passes through one or more outlets into the passenger space or spaces of the automobile. Such outlets, of course, may be controlled with any usual or desired shutter arrangement,

The heat exchange means for transferring the heat from the hot products of combustion to the ventilating air is especially designed to offer low resistance to flow of this ventilating air and also to the products of combustion issuing from the combustion chamber. This heat exchange means cooperates with the other features of the heater which permit the use of a low pressure blower requiring the minimum of operating current for its driving motor. The electrical igniter, in accordance with usual practice, is provided with a thermostatic switch which disconnects this igniter from its source of current when the heater attains normal operating temperature so that the entire heating apparatus places a minimum drain on the automobile electrical system. Certain features of the heater shown and described herein are claimed in my co-pending application. Serial No. 479,039, filed March 13, 1943, now abandoned.

In operating an automobile, it frequently happens that the automobile is stopped but the occupants of the vehicle remain therein while waiting for a friend or relative to arrive on a train or while one member of the party runs an errand or is otherwise absent for a relatively short period of time. While the vehicle is thus stopped, it is desirable to turn of! the automobile engine, but this can not be done and the occupants of the automobile remain comfortable in cold weather unless some heating means independent of the engine is provided. The resilient fuel reservoir I00 which I have illustrated is intended to provide for situations of this kind and will allow the heater to continue to operate for as much as half an hour or more after the automobile engine has been stopped.

This resilient reservoir may assume numerous forms, but in the particular embodiment shown, this reservoir which is interposed between the fuel pump 22 and solenoid valve 80 is composed of I upper and lower sheet metal cups I02 and I04 se- -centralportion of the diaphragm cured together by bolts I 06, or in any other suitable manner.

A flexible diaphragm I08 divides the resilient reservoir into upper and lower chambers I I0 and H2, respectively. The periphery of this diaphragm is gripped between radially projecting flanges H4 and H8 provided by the cups I02 and I04, respectively. and the center portion of this diaphragm is gripped between sheet metal plates H8 and I20 clamped together by bolt I22 and nut I24. A spring I26 is confined between plate H8 and cup I02 and serves to urge the central portion of the diaphragm downwardly to expel fuel from the chamber I I2 therebeneath.

The cup I02 has a depression I28 forming a guide forthe upper end of the spring I26 and a centrally located upwardly extending portion I30 provided with vent openings I32 for the upper chamber IIO. A cover I84 is aflixed to this extension and protects the openings I32 against dirt and dust. This cover has a sleeve I36 forming a guide for the upper end of the bolt' I22 which actuates an automatic switch that serves to stop the heater whenever the fuel in the chamber III is exhausted.

A bracket I38 is attached to the cup I02 and carries insulating blocks I40 to which is aflixed an electrical terminal I42 and one end of a spring switch member I44. The other end of this switch member carries a contact I48 which is urged downwardly by the resilience or the spring member I44. The upper end of the bolt I22 carries an insulating bloc}: I48 supporting a second switch contact I50 which moves up and down with the I08. When the chamber II2 beneaththis diaphragm contains fuel, the contacts I46 and I50 are in engagement as shown in Fig. 1. when the fuel in the lower chamber I I2 is consumed and no additional fuel is supplied thereto by the fuel pump 22, the central portion of the diaphragm I08 and contact I50 descend. Contact until switch member I44 engages stop pin I52 whereupon these contacts separate to break the electrical circuit therethrough.

The arrangement of the automatic switch controlled by the pressure reservoir in the operating circuit for the heater is best shown in the wiring diagram of Fig. 2. In this diagram the usual automobile battery is indicated by reference numeral I54 and it is to be understood that this battery may be connected to the automobile starting, lighting and ignition systems in the conventional manner. One side of the battery is grounded at I58 and the other side of this battery is connected to a manual switch I58 which is the operating switch for starting and stopping the operation of the heating apparatus. This switch controls I48 descends with contact I50 additional fuel will communication between the automobile battery and the electric motor 50 for the blower, the igniter coil 62 and the solenoid valve 30. The motor 50, coil 62 and solenoid valve 30 are all grounded, as indicated at I60, I62 and I64, respectively, and the usual thermostatic switch I66 is located in the igniter circuit to disconnect the igniter coil 62 from the battery when the heater attains normal operating temperature.

The automatic switch, comprising the resilient switch member I44 and contacts I46 and I50, is interposed between the manual switch I58 and the motor 50, coil 62 and solenoid valve 30, so that the last three elements are disconnected from the automobile battery whenever this automatic switch is opened, regardless of the position of the manual switch I58.

The spring I26 of the resilient reservoir I is slightly weaker than the spring of the fuel pump 22 so that when this pump is operating fuel is supplied to the engine carburetor and forced into the lower chamber II2 of the reservoir I60. This pushes the central portion of the diaphragm I08 upwardly against a spring I26, which is preferably so designed that it exerts a uniform force on the central portion of the diaphragm for all positions of this central portion. As long as the engine is operating, therefore, the reservoir I00 is ordinarily filled to its maximum capacity. This capacity may be sufiicient to hold any predetermined amount of fuel, it usually being suflicient to provide for approximately one-half hour of heater operation after the automobile engine has stopped. In a I have found that a capacity of eight ounces of fuel will provide for a heater operation of somewhat more than one-half hour.

When it is desirable to have heat in the passenger compartment of the automobile, the operator closes the switch I58. This opens solenoid valve 30, starts blower motor 50 and supplies current to ignition coil 62. The heater thereupon begins to operate and as soon as it attains normal operating temperature, thermostatic switch I66 cuts out igniter coil 62 to reduce the drain on the automobile battery. Since the heater oii'ers minimum resistance to air flow therethrough, the blower motor 50 may be made of minimum size and itself consumes little current. As long as the automobile engine operates, fuel will be supplied to compartment II2 as fast asit is consumed by the heater and this compartment will remain completely filled. If the engine is stopped, no

be supplied to the compartment II2, but the valves in the carburetor float bowl and outlet of the engine fuel pump will prevent reverse flow of fuel from the compartment I I2 of the pressure reservoir.

Stoppage of the automobile engine. however, will not interfere with the operation of the heating apparatus, as the downward force exerted by the spring I26 on the diaphragm I08 will force fuel from the chamber I I 2 to the jet 34 so that the heater will continue to be supplied with a combustible mixture as long as any fuel remains in the chamber II2. The period of time throughout which the heater will continue to operate after the automobile engine has been stopped will, of course, depend upon the fuel capacity of the Dressure reservoir and, as previously stated, it is usually desirable to make this capacity such that the heater will continue to operate from one-half hour to a full hour.

If the automobile engine is not started before the fuel in the resilient reservoir is exhausted, the

particular size and type of heater switch I66.

descent of the diaphragm will open the automatic switch contacts I46 and I50 Just before the fuel in the resilient reservoir is completely exhausted. This opening of the automatic switch will stop the motor 50 and result in closing of the solenoid valve 80, but will have no immediate effect on the igniter coil 62, since this coil is already disconnected from the battery by the open thermostatic However, When this thermostatic switch cools down and closes, no current can flow to the igniter coil because of the open contact I46 and I50.

If the manual switch I58 is left closed and the motor is again started, the engine fuel pump 22 will force fuel into the chamber II2 of the resilient reservoir to raise the diaphragm and close the automatic switch contacts I46 and I50. This will result in re-starting the heater, but if further heat is not required the operator may stop the heater by opening the manual switch I58.

From the foregoing it will be apparent that the automatic switch associated with the resilient reservoir does not interfere with the operation of the heater whenever the automobile engine is op erating, or as long thereafter as there is fuel in the chamber II 2. As soon as the fuel in this chamber becomes exhausted, the automatic switch contacts I46 and. I50 are opened to prevent unnecessary drain on the automobile battery and also to protect the against unnecessary operation. The particular resilient reservoir shown has a spring pressed dia phragm, but any otherequivalent resilient means could be used in lieu thereof, such for example, as a closed air dome.

My new and improved heating apparatus is particularly adapted for use on automobiles but may be applied with equal facility to other vehicles or for stationary use. It is to be understood that my invention is not limited to the particular details shown and described, but may assume numerous other forms and that the scope of my invention is defined by the following claims,

I claim:

1. Heating apparatus of the class described,-

comprising an internal combustion heater, an electrical igniter therefor, a pump for supplying fuel to said heater, a pipe lineconnecting said pump to the heater, .a fuel reservoir interposed in said pipe line. between the pump and the heater, said reservoir comprising a fuel chamber having a flexible diaphragm forming one wall of said chamber, spring means constantly urging said diaphragm against the fuel in said chamber to provide pressure for. feeding fuel from the reservoir to the heater when the pump is not operating, and switch means supported in fixed relation to said reservoir and connected. to said diaphragm for actuation thereby to open the ignition circuit when the quantity of fuel in the chamber falls below a'predetermined minimum.

2. Heating apparatus of the class described, comprising an internal combustion heater, .a pump for supplying fuel to said heater, a pipe line connecting said pump to the heater, a. fuel reservoir interposed in said pipe line between the pump and the heater, a spring closed valve in the pipe line between the reservoir and the heater and electrically operable means for opening said valve, said reservoir comprising a fuel chamber having a flexible diaphragm which forms one wall of said chamber, springmeans constantly urging said diaphragm against the fuel in said chamber to provide pressure for feeding fuel from the reservoir to the heater when the pump is not motor 50 and ignition coil 62 operating, and switch means supported in fixed and ventilating air to said heater, a pipe line connecting said pump to the heater, a fuel reservoir inter osed in said pipe line between the pump and the heater, said reservoir comprising a fuel chamber having a flexible diaphragm forming one wall of said chamber, spring means constantly urging said diaphragm against the fuel in said chamber to provide pressure for feeding fuel from the reservoir to the heater when the pump is not operating, and switch means supported in fixed relation to said reservoir and connected to said diaphragm for actuation thereby to open the circuit of said electrically-driven blower when the quantity of fuel in the chamber falls below a predetermined minimum.

4. Heating apparatus of the class described comprising an internal combustion heater which includes electrically energized means adapted to interrupt operation of the heater when de-energized, a pump for supplying fuel to said heater, a pipe line connecting said pump to the heater, a fuel reservoir interposed in said pipe line between the pump and the heater, said reservoir comprising a fuel chamber of suflicient volume to sustain operation of said heater for a period after operation of the pump is discontinued, said chamber having a flexible diaphragm said chamber, spring means constantly urging said diaphragm against the fuel in said chamber, and switch means connected to said diaphragm for actuation thereby to open the circuit of said electrically energized means when the quantity of fuel in the chamber falls below a predetermined minimum.

5. Heating apparatus of the class described comprising an internal combustion heater, an electrical igniter therefor, a pump for supplying fuel to said heater. a pipe line connecting said pump to the heater, 9. fuel reservoir interposed in said pipe line between the pump and the heater, 50

a, spring closed valve in the pipe line between the electrical means, causing said forming one wall of reservoir and the heater and electrically operable means for opening said valve, an electrically driven blower for supplying combustion and ventilating air to said heater, said reservoir comprising a fuel chamber having a flexible diaphragm which forms one wall of said chamber, spring means constantly urging said diaphragm against the fuel in said chamber to provide pressure for feeding fuel from the reservoir to the heater when the pump is not operating, a source of electrical energy and a circuit which includes said energy source, said electrical igniter, said valve operating means, and said blower, and switch means operatively connected to said diaphragm for actuation thereby to open the said circuit when the quantity of fuel in said chamber falls below a predetermined minimum.

6. Heating apparatus of the class described comprising an internal combustion heater, means for supplying combustion and ventilating air to said heater, a reservoir comprising a pair of cups having a diaphragm clamped between them to form a fuel chamber and a spring chamber, a pump for supplying fuel to said heater connected into said fuel chamber and a pipe extending from said chamber to the heater, a spring in the spring chamber interposed between the diaphragm and one of said cups and urging the diaphragm against the fuel in the fuel chamber to provide pressure for feeding the fuel from the reservoir to the heater, switch means controlling said air supply means and connected to said diaphragm for actuation thereby, said switch means being adapted to be opened by movement of the diaphragm when the quantity of fuel in said fuel chamber falls below a predetermined minimum, said air supply being shut oil by said opening of the switch means.

HENRY J. Dr: N. McCOLLUM.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 1,348,916 Winslow Aug. 10, 1920 1,357,598 Thompson Nov. 2, 1920 1,385,845 Scott July 26, 1921 1,391,385 Jacobsen Sept. 20, 1921 2,357,404 Heymann et a1, Sept. 5, 1944 

